const setRemUnit = () => {
  const docEl = document.documentElement;
  // IPhone6下750像素来设计，实际像素375px，1rem为50px
  const rem = docEl.clientWidth / 7.5;

  docEl.style.fontSize = `${rem}px`;
};

const pageShowCallback = e => {
  if (e.persisted) {
    setRemUnit();
  }
};

document.addEventListener("DOMContentLoaded", setRemUnit, false);

// reset rem unit on page resize
window.addEventListener("resize", setRemUnit, false);

// reset rem unit on page show
window.addEventListener("pageshow", pageShowCallback, false);

export default setRemUnit;
